This invention relates to a power supplying apparatus and method for a plurality of electric loads remote from a power supply, and also to a semiconductor circuit apparatus and an intensive wiring apparatus for transmission of control information for use with the power supplying apparatus and method.
In a conventional power supplying apparatus for a vehicle, a power supply carried on the vehicle and each of several electric loads are connected to each other by a long power supply line with a fuse interposed therein. When a power supply line is short-circuited, the fuse is blown to disconnect the electric load from the power supply.
In control of electric loads of a conventional vehicle, a so-called multiplexing wiring system is known wherein controllers for individually controlling a plurality of electric loads are integrated into a smaller number of controllers having a communication function and a calculation function so that control signals for the electric loads are calculated by the smaller number of controllers and the control signals are transmitted to terminal equipments connected by communication lines to control several electric loads connected to each of the terminal equipments (refer to, for example, U.S. Pat. Nos. 4,771,382, 5,113,410, 4,855,896 and 5,438,506).
However, power supply lines are usually wired from a power supply directly to individual electric loads or to driving circuits for the electric loads, and the number of power supply lines is equal to or larger than the number of electric loads and the floor or the inside of the body of a vehicle is full of wiring lines.
Accordingly, basically it is a principle object of the present invention to provide a novel power supplying apparatus for a vehicle. More specifically, it is an object of the present invention to reduce power supply lines of a power supplying apparatus for a vehicle. It is another object of the present invention to eliminate a fuse. It is a further object of the present invention to provide a novel power supplying method. It is a still further object of the present invention to provide a novel semiconductor circuit apparatus for use for supplying power. It is a yet further object of the present invention to provide a novel intensive wiring apparatus integrated with a power supply control system. It is a yet further object of the present invention to provide a novel power supplying apparatus for a particular electric load of an automobile. It is a yet further object of the present invention to provide a novel apparatus for detecting short-circuiting of a power supply line. The objects recited above are solved by different solving means disclosed hereinbelow or in the appended claims.
According to a first aspect of the present invention, since two power supply lines are led out from one of poles of a power supply such that power can be supplied from both of the power supply lines to electric loads, a novel power supplying apparatus wherein, even if one of the lines is short-circuited, supply of power can be maintained from the other line can be provided.
According to another aspect of the present invention, since an electric switching apparatus for controlling connection and disconnection between a power supply line and an electric load is provided in a relay circuit provided between the power supply line and the electric line such that, when the power supply line is short-circuited, the switching apparatus is operated to disconnect the electric load from the circuit, a fuse can be eliminated.
According to a further aspect of the present invention, since power transmission lines of a closed loop are formed from power supply lines connected to one of two poles of a power supply such that power can be supplied from the opposite sides of a connection point of an electric load so that, even if short-circuiting or disconnection occurs with one of the transmission lines, supply of power can be continued from the other side of the transmission line, the number of electric loads which are rendered uncontrollable by a failure of a transmission line can be reduced.
According to a still further aspect of the present invention, since a network is formed from power supply lines similar to communication lines to construct a multiplexing wiring system which can handle both of control signals and power, also the power supply lines are aggregated and the number of electric wires can be reduced.
According to a yet further aspect of the present invention, since power supplying apparatus for electric loads for an air conditioner control unit, a power train control unit, a lamp control unit, a navigation unit, an anti-lock braking control unit, a window opening and closing motor control unit, a display circuit control unit for an instrument panel, a rear defogger controlling unit, a beacon control unit and so forth are formed from a novel power supplying apparatus of the present invention, those electric loads in an automobile can be controlled with a reduced number of wiring lines.